.TH std::experimental::ranges::find_first_of 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::experimental::ranges::find_first_of \- std::experimental::ranges::find_first_of

.SH Synopsis
   Defined in header <experimental/ranges/algorithm>
   template< InputIterator I1, Sentinel<I1> S1, ForwardIterator I2,
   Sentinel<I2> S2,

             class Proj1 = ranges::identity, class Proj2 =
   ranges::identity,
             IndirectRelation<projected<I1, Proj1>,                     \fB(1)\fP (ranges TS)
                              projected<I2, Proj2>> Pred =
   ranges::equal_to<> >
   I1 find_first_of( I1 first1, S1 last1, I2 first2, S2 last2, Pred
   pred = Pred{},

                     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{} );
   template< InputRange R1, ForwardRange R2,

             class Proj1 = ranges::identity, class Proj2 =
   ranges::identity,
             IndirectRelation<projected<ranges::iterator_t<R1>, Proj1>,
                              projected<ranges::iterator_t<R2>, Proj2>> \fB(2)\fP (ranges TS)
   Pred = ranges::equal_to<> >
   ranges::safe_iterator_t<R1> find_first_of( R1&& r1, R2&& r2, Pred
   pred = Pred{},

                                              Proj1 proj1 = Proj1{},
   Proj2 proj2 = Proj2{} );

   1) Searches the range [first1, last1) for any of the elements in the range
   [first2, last2), after projecting the ranges with proj1 and proj2 respectively. The
   projected elements are compared using pred.
   2) Same as \fB(1)\fP, but uses r1 as the first source range and r2 as the second source
   range, as if using ranges::begin(r1) as first1, ranges::end(r1) as last1,
   ranges::begin(r2) as first2, and ranges::end(r2) as last2.

.SH Parameters

   first1, last1 - the range of elements to examine
   r1            - the range of elements to examine
   first2, last2 - the range of elements to search for
   r2            - the range of elements to search for
   pred          - predicate to use to compare the projected elements with
   proj1         - projection to apply to the elements in the first range
   proj2         - projection to apply to the elements in the second range

.SH Return value

   Iterator to the first element in the range [first1, last1) that is equal to an
   element from the range [first2, last2) after projection. If no such element is
   found, an iterator comparing equal to last1 is returned.

.SH Complexity

   At most (S * N) applications of the predicate and each projection, where S =
   distance(last2 - first2) and N = last1 - first1.

.SH Possible implementation

   template<InputIterator I1, Sentinel<I1> S1, ForwardIterator I2, Sentinel<I2> S2,
            class Proj1 = ranges::identity, class Proj2 = ranges::identity,
            IndirectRelation<projected<I1, Proj1>,
                             projected<I2, Proj2>> Pred = ranges::equal_to<>>
   I1 find_first_of(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = Pred{},
                    Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{})
   {
       for (; first1 != last1; ++first1)
           for (ForwardIt it = first2; it != last2; ++it)
               if (ranges::invoke(pred, ranges::invoke(proj1, *first1),
                                        ranges::invoke(proj2, *it)))
                   return first1;
       return first1;
   }

.SH Example

    This section is incomplete
    Reason: no example

.SH See also

   find_first_of searches for any one of a set of elements
                 \fI(function template)\fP
   find          finds the first element satisfying specific criteria
   find_if       \fI(function template)\fP
   find_if_not

.SH Category:
     * Todo no example
